Sex and racial differences in bladder cancer presentation and mortality in the US

Abstract

Background: Sex, race, and age at diagnosis have a significant impact on mortality from bladder cancer (BC). Women, African Americans of both sexes, and the elderly, all experience higher mortality rates. Tumor grade, stage, and histologic type at presentation also affect outcome. To determine whether age and tumor characteristics alone explain the excess hazard of death from BC observed in some demographic groups, the authors queried the Surveillance, Epidemiology, and End Results (SEER) limited-use database for the presentations and outcomes from BC between 1990 and 2005.

Methods: Tumors were characterized by grade, stage, and histologic type. Hazards rates for BC-specific mortality were compared by race and sex using a piecewise Cox regression model, adjusting for factors (age, stage, grade, and histologic type) that differed significantly between the groups that were compared.

Results: Excess hazard of death from BC was present during the first 2 to 3 years of follow-up among women and during the first 4 years of follow-up among African Americans. Adjustment for age and tumor characteristics eliminated approximately 30% of this excess hazard in sex comparison among whites. In sex comparison among blacks and in racial comparisons within each sex, approximately 50% to 70% of excess hazard could be eliminated by adjustment.

Conclusions: Significant differences in tumor characteristics and age at presentation did not fully account for the excess hazard of death from BC among women and African Americans. Other factors, such as choice and efficacy of therapies, differences within a given tumor characteristic group, and/or host factors also may play important roles.